LINQ "not in" datatable

How can I return datatable rows which are not matching in another datatable?

Return all rows from DT1 which are not found at DT2 using column DT1.Manufacturer values not in DT2.MFr

Schema is different on both datatables.

1 Like

Hi @ajh ,

If the Tables share the exact same schema, then this could you try this?

DT1.AsEnumerable().Except(DT2.AsEnumerable(), DataRowComparer.Default).CopyToDataTable()

If you want to do so on the basis of the two columns, then could you give this a try?

(From r1 In DT1.AsEnumerable()
Group Join r2 In DT2.AsEnumerable()
On r1("Manufacturer").ToString.Trim Equals r2("MFr").ToString.Trim Into gj = Group
From g In gj.DefaultIfEmpty
Where IsNothing(g)
Select r1).CopyToDataTable()

Kind Regards,
Ashwin A.K


Check below for your reference

Hope this will help you


Hi there @ajh,
I trust you are well!

Are you able to provide the schema for the Tables/confirm they also contain the “Manufacturer” field?

Thanks once again for your continued support,

we can implement like:

drUnmatched | List(Of DataRow)
We do defensively use the CopyToDataTable depending if we got returned data rows in order to avoid a no rows … exception


(From d1 In dt1.AsEnumerable
Where  Not dt2.AsEnumerable.Any(Function (d2) d2(0).toString.Trim.Equals(d1(0).toString.Trim))
Select r=d1).toList

About the other approaches:

Set Operation Except:
It will handle all columns and will remove duplicated rows from the result. This can lead to negative side effects

Left Join (LINQ: Group Join)
In case of more rows matching the join condition will occur, then additional rows will be returned as in the nature of a join all matching rows will be paired together.
dt1: A1|1, A2|2
dt2: A1|*, A1|+, A3|$

will have a left join result of

as first A1 will be joined with both right A1
and second A1 will be joined with both rigth A1

Find starter help here:
GetLeftWhenMatchRight_1Col_AnyApproach.xaml (14.8 KB)

Schema is completely different between datatables, I will try ashwin.ashok two columns method


You can also use the below LINQ query to get unmatched rows.

Please try if useful.

DT1.AsEnumerable.Where(Function(sourceRow) Not DT2.AsEnumerable.Any(Function(destRow) sourceRow(“Manufacturer”).ToString = destRow(“MFr”).ToString)).CopyToDataTable

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